The use of a bag and box combination generally employs some form of dispensing fitment fixed to a bag and that projects through an opening in the sidewall of the outer rigid container. During shipment, the passage through the fitment is sealed, for example, by means of a membrane or by welding the bag to the inside of the mounting flange of the fitment, i.e. on the side of the fitment mounting flange remote from the outside container so that the bag actually covers the passage through the fitment. In most cases, both the fitment membrane and bag and a cap or plug or the like at the exposed end of the fitment are used to seal the fitment during shipment.
While these sealing devices seal the bag and box combination during shipment, it is obviously necessary to open the passage through the fitment for dispensing of materials from the bag. This opening operation generally employs an external valve that is secured to the fitment in place of the cap or plug and is fitted with some means for puncturing the bag portion or membrane that seals the fitment passage.
Obviously, these systems are cumbersome and require that the control valve be attached at the point where the material is to be dispensed from the bag. This valve must remain in place until the bag has been emptied which makes relocating of the bag and box more difficult. Alternatively the valve may be attached and the unit shipped with the bag and valve in place, but this requires an oversized pallet thereby increasing the cost and increases the risk of in transit leakage.
A review of the literature indicates that gate valves for use in rigid containers have been known for many, many years, see for example, U.S. Pat. No. 88,008 issued Mar. 23, 1869 by Chase et al., U.S. Pat. No. 521,832 issued Jun. 26, 1894, U.S. Pat. No. 634,730 issued Oct. 10, 1899 to Howe et al. or more recently, U.S. Pat. No. 3,321,175 issued May 23, 1967 to App.
The Chase et al. patent describes a plate or gate valve that is moved between the open and close position by pivoting on an axis formed by a rigid shaft which is rotated to adjust the position of the plate. This is common to all of the above patents. Also, all of the above patents relate to application of such valve to rigid structures (as opposed to flexible bags) so that a valve plate may easily be moved from open to close position without interference with the structure to which it is connected).
The Chase et al. patent provides a system wherein the valve plate is contained within a rigid block and the movement of the valve plate is confined by the block to the width in the block structure. This requires that the block structure be sufficiently large to contain the valve plate throughout its movement and in both its open and closed positions and thus renders the device relatively bulky and ineffective for many purposes.